Board Thread:General Discussion/@comment-4785766-20170829171219/@comment-117.199.157.2-20180107194110

 Let me add a bit to your 'speculation': 

Nero's mother died, Either to save Virgil or by getting caputed and killed in revenge against Vergil. Vergil was devastated and felt that he was weak and failed again just like when he was young, he left Nero in orphanage because he felt that if the boy was close to him than he too would share the same fate.

Nero may or may not have attained partial devil trigger in his arm due to trauma of this scene.